va_list ARM changes

[Johannes Pfau]

Am Fri, 31 Aug 2012 12:49:37 +0100
schrieb Iain Buclaw <ibuclaw at ubuntu.com>:

> Part of where you are going wrong is that 'va_arg (va_list, TypeInfo,
> void*)' should only be used when the static type is indeterminable.
> This is typically only for structs and classes.  All basic types
> should go through the normal va_arg template functions - these
> actually get expanded intrinsically by the gcc backend and *do* the
> right thing, even for your float example.

OK, then everything is working as expected.
> 
> Now that is not to say that you can't use 'va_arg (va_list, TypeInfo,
> void*)' for basic types, but you do need to be aware of type
> promotions when it comes to va_args. :-)
> 
> Eg:
> 
> void main()
> {
>   test2("", cast(float)3.45f, "TestTest");  // float is promoted to
> double when passed as a vararg.
> }
> 
> void test2(string input, ...)
> {
>   double f;
>   string s;
>   va_list list;
>   va_start(list, input);
>   va_arg(list, typeid(typeof(f)), &f);
>   va_arg(list, typeid(typeof(s)), &s);
>   va_end(list);
>   writefln("%s %s", f, s);
> }
> 
> 
> And you'll see that test2() in your paste works.
> 
Still doesn't work for me, but if basic types should not be used with
that va_arg overload and as the templated version works fine anyway it
doesn't matter.